I was a little shocked – and delighted – to find Inayat Bunglawala announcing that he is going to organise a counter-demonstration to Anjem Choudary's group Islam4UK, which is planning to call for the implementation of their version of sharia law at a rally on Saturday 31 October.

My organisation, British Muslims for Secular Democracy (BMSD), had been working closely with likeminded British Muslim and non-Muslim democrats in planning a demonstration to coincide with Anjem's anti-democracy march and protest against freedom. Last week a Facebook group was also set up to float the idea and ignite people's interest. We had planned to make a formal announcement on Monday, but it makes sense, in the circumstances, to bring that announcement forward.

Our counter-demonstration is based on our belief in, and commitment to, those liberal values that define the British state, including legal and constitutional equality for all, equal rights for women and minorities, and religious freedom, including the right to be free of faith. We are turning out to defend all of these virtues of a secular democracy that Islam4UK so despises and daydream of taking away from the British public.

Indeed, the irony is that these are the values which allow Anjem Choudary to protest and promote his grossly illiberal message in the first place. But Choudary often abuses the tolerance our society affords him, and that's why we decided something had to be done. Many established Muslim groups have not taken enough practical steps to oppose groups such as al-Muhajiroun or Islam4UK. BMSD was launched last year and we have decided to take the initiative by spearheading this campaign to demonstrate our commitment to democracy and freedom.

I am excited that Bunglawala is also joining the fight for liberalism. It seems obvious to me that he has been on a quite extraordinary personal journey in recent months. Last month, he wrote a brave article about gay rights and the appalling abuse homosexual Muslims sometimes receive. This is a remarkable and welcome development – and a clear endorsement by Bunglawala of the values which define our country. However it is not clear whether such views are personal or reflect a broader change of attitudes within the Muslim Council of Britain, some of whose most senior members remain closely connected with, and openly support, theocratic parties in south Asia and the Middle East that oppose of the secular liberal democracy which we cherish.

I would urge all British Muslims and non-Muslims to build on the brave steps we have already taken and condemn theocratic organisations everywhere who seek to segregate Muslims from mainstream society on the basis of twisted ideological interpretations and impose an intolerant way of life upon them, calling it sharia. This is the basis on which British Muslims for Secular Democracy was founded. We believe that a commitment to plural and liberal values is necessary everywhere around the world.

Bunglawala has already taken some important steps – and I hope he will take another by joining me in condemning all theocratic parties and their grotesquely illiberal views. The Muslim community in Britain is going through a period of rapid change. New voices are emerging all the time. Our message is simple: we are fed up with the old leadership that has betrayed us and everything we believe in.

I make the same appeal to Bunglawala as I do to all of you – Muslim or otherwise – please come along on Saturday 31 and show your support by signing up here for secular democracy. We would love you to join us and raise a voice against all theocratic values and parties – whoever they are.